Superheater.



H. B. OATLEY L N. T. IVICKEE.

SUPERHEATER.

APPLICA'TION FILED FEB.15V.1916.

Lm. I Patented May 30,1916.'

2 SHEETS-SHEET I.

] niv@ wrom( H. BQUATLEY & N. T. MCKEE.

SUPEHHEATER.

APPLICATION FILED FEB15| 1916.

Patented. May 30,1916.

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HENRY n. OATLEY, or nhnsnire, ann naar, Termin Merten, or YoNKERs, NEWYORK, vassrenons 'ro Locoiaorrvn surnnrrna'rnn minnaar, or New venir, n.Y.,

A CORPORATION 0F DELAWARE.

SUPERHEATER.

Specification of Letters Patent.

Patenten May so, raie.

Application filed February 15, 1916.` ySerial No. 73,3735. v

-certain heat losses possible in former arrangements are minimizedor/wholly obviated, whereby the steam 1s more efficiently superheated,deposits of soot and 'cindcrs prevented', and the friction lossesreduced."

With superheaters of this type, used priucipally in connection 'withlocomotives and comprising, as isunders'tood bythose familiar with theart, a loop or loops located in fiues, the pipes carrying the steam areex posed to the most intense heat near the firebox endvof the lues. Fromthis point forward the combustion gases are gradually cooled by thesurrounding water as they travel forward until their temperaturebecomes, under certain circumstances, lower than that of the steamtraveling in the same direction inside of the i'ast leg ot' thesuperheater unit. This happens particularly where the tlues are ofrelatively great length, and is objectionable for the reason that thesuperheated steam again gives up part of its heat to the combustiongases which then leave the iiues at a temperature too high for besteconomyg 'The present invention reduces this effect to a minimum.

Even where from the conditions of the case the danger of the superheatedsteam again losing part ofv its heat to the, surrounding gases isabsent, the present arrangement,

marks an improvement in that most oi the heat transfer from the hotgases to the steam occurs under the most favorable conditions from athermodynamic standpoint. that isI on the .couuterflow principle.reducing the number of reversals which the steam experiences in itscourse through the element, the friction losses are considerablyreduced. l

We are aware that others have known of the loss of eliiciency abovepointed out and its cause,l and that arrangements have been proposed ltoobviate it; and to obtain the advantages of counterfiow heating, but asfar as We know none of the prior inventions has used the present oranalogous means in the drawings which form part of the presentspecification and which illustrate constructions embodying the underling principle, Figure 1 represents,'partly 1n section and partly inelevation, a superheater unit of the preferred form of our in- `ventiontogether with so much of the adjacent parts of the boiler and headers asis necessary to show the arrangement relative to these parts; Figs. 4t,6, and 8 show moditications; While Figs, 2, 3, 5, 7, and .9 showsections taken on lines 2 2, 3?, 5 5, 7-7, and 9-9 respectively. in allof the guresthe arrows indicate the direction of the steam and gas How.

Referring first to Figs. 1, 2 and 3, reference numerals l and 2designate reaped.

tively the saturated and superheated steam headers, While -3 designatesa iue within which. is located a superheater unit. In the arrangementhitherto most extensively used v the part of the unit lying within theflue is made up of yfour lengths of pipe connected appropriately to'eachother by return' bends and to the 'two headers in such manner that Vthesteam, leaving .the saturatedsteam.,

header, traverses the four lengths successively,thereai`ter passing tothe superheated steam header, whence it is carriedto the enginecyl-inders. nithe present arrangement, as illustrated in Figs. l, 2, and3, the pipe e leading from the saturated steam header is subdivided at 5into three parts, 8, 9,10, each of substantially the same diameter aspipe 4;,

and reunited into a single pipe 4 at or near.

the rear end of the flue 3. The pipe 4 is joined by return bend G to thelength 7, which is also of substantially the' same diameter as pipe 4,and the front end of which is continued and attached to superheatedsteam header l lhe operation oi the device will be evident. Steam 1scarried 'from the steam dome or other desired point to the headerv Vl bythe usual means known to those :ta-

illustrate or describe here'. Passing thence through the pipe 7 and toheader 2 as a singlev stream. The cross-seotions of pipes 8, 9, 10 and 7being substantially the same the steam travels at a comparatively slowrate toward the fire-box end of 'the flue, the principal part of theheating occurring .during this passage. T he return through pipe 7occurs very rapidly, the single pipe carrying' all the steam. .Thevchance for transfer of heat from the superlieated steam to thecombustion gases in the front part of the flue,

ing a flu e.

where the latter have been cooled by the surrounding water toa'temperature below that of' the superheated' steam, is correspondinglysmall. The heating, on the other hand, in the other three pipes hasVoccuired under conditions conducive to high eiliciency. Manifestly thenumber of streams into which the ingoing steam is subdivided may be'some other number than three; whilel the headers need not be arrangedas shown, but

may have any other preferred positions. It

is of course understood that there are any desired number of such units,each occupy- Figs. 4: and 5 illustrate a Inodication, showing theinventive idea applied to a form, wherein the steam, instead of beingcarried to the superheat'ed steam header 2 afterl traversing the pipesin flue 3, is carried through a second Set of pipes lying in a secondflue, 3', and then to the header 2. The unit i's here shown ascomprising two in-carrying branches, 8 and `9', springing from thesingle pipe 4f at point 11, and reuniting into single pipe 7 at pointl2; the arrangement in the second flue being similar. Instead ofdividing the steaml on its way toward the lire-box into several streamsand thuis retarding the flow in that direction relatively to that in theopposite'direction, thesteam may be carried in the former direction by apipe larger in `dinmeber than the one by which it is returned toward theheader. lSuch an arrangement is .shown in Figs. `6 and 7. rIhe steamtravels inward slowly through pipe 8 and out comparatively fast. throughpipo, 7, this being repeated in the second flue, after which the' steamgoes to` header 2..A Figs. 8 and 9 illustrate the same principle appliedto a Field tube arrangement, the two coaxial elements8 and` 7 ol whichare so proportioned that the annular space 13 between them is largerthan the space in the inner one. In the latter two arrangements the sameadvantage is obtained of returning the 'steam rapidly to the froi'itfrom the lire-box end,

ward course is not performed as efficiently.

An advantage incidental to all the forms of unit illustrated overpreviously suggested though the heating of thel steam onkits informs inlwhich ceiling or looping the ingoing pipe for the purpose oflengthening the 'path was resorted to4 is, that there are no abruptchanges in the cross-section for the gases and-.the liability of sootand cinder deposits is correspondingly reduced.

It will evident that various other modiications may be made within thespirit of the following claims.

`We claim- 1. In a superheater of the class described, a unit comprisingtwo portions carrying'the steam toward and from a source of heatrespectively, the former portion having the 'grea ter cross-sectionalarea.

Y, 2. ln a. superheater of the class described,

"'a unit comprising two portions carrying the steam toward and from asource of heat respectively, the former portion comprising a pluralityofdivisions the combined crosssectional area of-which is greater thanthat of the latter.

3. In a boiler provided with heating tubes carrying products ofcombustion, the combination with one or more of said tubes of asupcrheaterunit of the class described 1ocated in said tube or tubes andcomprising portions carrying steam in directions against and with thecurrent of the products of coinbustion respectivelyi` the former portionor portions having a "greater cross-sectional area than the latter. "i i4. In a boiler provided with heating tubes carrying products ofcombustion, the combination with one of said tubes of a superheater unitof the class described-located'f'in` said tube and' comprising twoprtions carrying steam in directions against vand with' the current ofthel'products `of combustion respectively, the former portion having agreater cross-sectional area `than the latter.

5. In a boiler provided-with heating tubes carrying products ofcombustion, the combination with oneof `said tubes of a superheater unitof the class described located in said tube and comprising two portionscurrying steam in directions against and with the current ot theproducts of combustion respectively, the former portion bcingisubdividedinto a plurality of parts each of substantially the same cross-ectionalarea as the latter portion.

HENRY B. OATLEY.. NEAL TRIMBLE MCKEE.

